Field
This present subject matter relates generally to an apparatus and method for measuring tensile load.
Discussion of the Related Art
Fasteners, such as screws and bolts, are ubiquitous in machinery and structural design. In most applications, they are loaded in tension in order to place clamped components in compression and hold assemblies together. There are many ways to measure fastener tensile loads, including but not limited to fastener length measurement and load indicating devices. Most tensile load measurements fall into two categories: indicating a fastener has reached a particular tensile load, and direct measurements of an existing tensile load. More rarely, the need arises to measure a peak load experienced by a fastener exposed to a range of loads over a period of time.
Existing devices have many drawbacks, as they must be observed in the installed condition. Some rely on inks or dies to indicate a load is reached, and are unsuitable for some environmental conditions. Still others are limited to indicating when a particular tensile load is achieved, and/or indicate the magnitude of a current tensile load without retaining any information about prior loads. These and other drawbacks are solved in the exemplary embodiments described below.